There are, at present, hundreds of thousands of patients in the United States with end-stage renal disease. Most of those require dialysis to survive. United States Renal Data System projects the number of patients in the U.S. on dialysis will climb past 600,000 by 2012. Many patients receive dialysis treatment at a dialysis center, which can place a demanding, restrictive and tiring schedule on a patient. Patients who receive in-center dialysis typically must travel to the center at least three times a week and sit in a chair for 3 to 4 hours each time while toxins and excess fluids are filtered from their blood. After the treatment, the patient must wait for the needle site to stop bleeding and blood pressure to return to normal, which requires even more time taken away from other, more fulfilling activities in their daily lives. Moreover, in-center patients must follow an uncompromising schedule as a typical center treats three to five shifts of patients in the course of a day. As a result, many people who dialyze three times a week complain of feeling exhausted for at least a few hours after a session.
Given the demanding nature of in-center dialysis, many patients have turned to home dialysis as an option. Home dialysis provides the patient with scheduling flexibility as it permits the patient to choose treatment times to fit other activities, such as going to work or caring for a family member. One requirement of a home dialysis system is a reliable water purification system as dialysis requires purified water for mixing with a dialysate concentrate. Even trace amounts of mineral concentrates and biological contamination in the water can have severe adverse effects on a dialysis patient. In addition, water purification systems in typical dialysis systems must be capable of purifying the very large quantities of water required to run a full dialysis session.
Unfortunately, existing water purifications have drawbacks that limit practical usage of such systems in a home dialysis system. Existing water purification systems are large and bulky, often being as large as a residential washing machine and weighing over three hundred pounds. Such systems also very often consume large amounts of energy in order to purify relatively small amounts of water. In sum, existing water purification systems are bulky and expensive, making them practically unsuitable for use in the average patient's home.